Reproducer



Patented Jan. 24, 1928. I

UNITED STATES HARRY E. 11318, 01 LA GRANGE, ILLINOIS,

I SUPPLY COMPANY, 01 CHICAGO, ILLINOIS,

ASSIGNOB TO KELLOGG SWITCHBOABD A CORPORATION 01' ILLINOIS.

PRODUCER.

Application filed December '8, 1934. Serial I0. 758,018.

1 In 'loud speakers or reproducers of the t pe now in use the'construction is such that z t e diaphragm is affected by the magnets when current is passing through the coil windings, to cause the diaphragm to vi- 1 brate to emit sound. The diaphragm in the vicinity of the pole ieces is cause dip due to force exerted y the magnets in attracting the diaphragm and this diping of the diaphragm at its center prouces a ripple or chatter when the current undulates and causes distortion of the sound. To overcome this objection I have devised means of connecting the windings of the reproducer magnets of m invention as so that as the current passes t rough the windings the diaphragm is attracted and released in a manner to eliminate said chatter or ripple as this method of connecting the windings causes one of the magnets to act so as a buffer or check on the diaphragm activity both toward and from the pole pieces,

thus preventing distortion.

Another feature of my invention is the provision of a supporting means for the pole pieces and associated apparatus, w v

are su ported as a whole on springs; and provi e adjustable means associated with this supporting means for moving ,the supporting means as a whole up or down in 1ts 4c cnclusing cup to vary the air gap between the pole pieces and the diaphragm to obtain the maximum efliciency for a clear and perfect reception of sound.

The above features as well as others not s eciiically pointed out will be more fully p escribed in the ensuing specification and .ap ended claims.

or a more complete understanding of my invention reference may be had to the acclearly illustrate hich I provided companying drawing in which like reference 64} haracters 1n the several views denote like parts and in which' Fig. 1 is ja plan view of my invention- F g.2 is a right side view of Fig. 1' Fig. 3 is a plan view of the repro with the cap and diaphragm removed the interior apparatus; Fig. 4 1s a sectional view along the line 4-4 of Fig. 1; ac

;Fig. 5 is a sectional view along the line 5-5 of Fig. 1 and Fig. 6 diagrammaticall producer and the metho coils of the reproducer.

Referring now more in of the reproducer near illustrates the re"- of connecting the detail to the re producer oi my mventiou it comprises a cup shaped member 2 formed-of suitable metal such as brass and in which-I adjustably secure the mechanism of the reprom ducer. Three ins 3 equall spaced apart a are secured to t e base 4 of t e cup member 2 and project u from the face 5 of the base 4 mto the interior of the cup member 2. A-

disk 6 of suitable metal such as brass is pro- 7 vided with three orifices 7 which are in alignment with the three pins 3 which extend up into these three or1fices7 when the disk 6 is placed into position. A helical sprin 8 is placed around each pin 3 and rests tween the face 5 of the base 4' of the cup member 2 and the bottom face 9 of the disk 6 for urposes as will presently be described. T e base 4 of the cup member 2 is disk 6 which rests upon the helical springs 8 is provided with a tapped orifice 11 1n ahgnment with the central orifice 10 in the on member 2. A threaded stud 12 provide with a slotted head 13 passes through the orifice 10 in the base 4 of the cup member 2 and has screw threaded engagement with the tapped orifice 11 in the disk 6 for puroses as will presently be described.

Angular pole pieces 14 and 15 are secured on to the disk 6 by means of screws 16 which pass through suitable orifices 17 in the disk 6 and have screw threaded engagement with with a central orifice 10 and the 35 suitable tapped orifices 18 in the extended portions 14and of the pole pieces 14 and 15. The portions 14 and 15 of the pole pieces 14 and 15 which extend upward in proximity to the diaphragm 2O carry the magnet'coils or spools 21 and 22. The per- I manent magnet 23 is placed within the cup member 2 and is semicircular in shape an is constructed of steel or other suitable material which is permanently magnetized and fits along the inner periphery of the on member 2 with its ends 23' and 23 terminating over the portions 14 and 15 of the pole pieces 14 and 15.. Screws 24 and 25 are provided and pass through suitable orifices in the ends 23 and 23' of the ermanent magnet 23 and have screw threa ed engtagement with suitable tapped orifices in t e disk 6, which when turned down clamp the permanent magnet 23- in position against the portions 14' and 15 14 and 15. The on member 2 is provided with external threa s 30 at its forward end upon which is screwed a cap 31 of suitable material such as hard rubber or bakelite. The cap 31 when screwed down securely clam s the diaphragm 20 against the cir-' cum erential en of the cup member 2. The cap 31 is provided with an integrally formed extended member 32 which is internally threaded and is adapted to receive a suitable sleeve member for connecting it as a unit to a projector or horn.

A pair of binding posts or terminals 35 and 36 are secured to the as both are alike a detai description of one willsufiice. The terminal 35 com rises a stud 37 which passes throu h a suitable insulation sleeve which exten s throu h a suitable orifice in the side wall 38 0 the cup member 2. Nuts 3 and 40 are provided and have screw threa ed engagement with the protruding ends of thestud 37 and clamp the same in sition against rotation, and suitable insulation washers 41 are placed between the nuts 39 and 40 to insulate them from the cup member 2. A suitable terminal 42 is secured to the stud 37 in any suitable manner and the respective terminal end of the winding of the magnetcoil 22 is soldered thereto. A suitably formed clip 43 is clamped in position on the stud 37 bv a nut 44 and this clip 43 is adapted to receive the external cord terminal connection. A terminal 45 is also provided with terminal 36 to which is soldered the terminal end of the magnet coil 21 and a clip 46 secured to the terminal 36 by means of a nut 47 is adaptedto receive the other external cord terminal. p v

Having described in detail the apparatus of the reproducer of my invention I will now describe how the disk 6 and its supported apparatus is adjustably secured as a whole m the cup member 2. The disk 6 of the pole pieces cu member 2 and led connection and the tension of pieces 14 and 15 in association with and its supported apparatus may be adjusted as a whole up or down relative to the clamped diaphragm 20 to change the air ga between the diaphragm 20 and the po 8 pieces 14 and 15. When the stud 12 is turned in a clockwise direction through the agency of a suitable tool which is placed in the slot 50 in the head 13 of the stud 12, due to the fact that the stud 12 is in screw threaded engagement. with the tap ed orifice 11 in the disk 6 thisturning of this stud 12 in a clockwise direction permits the helical springs 8 around the pins 3 between the face 5 of the base 4 and the face 9 of the disk 6 to force the disk 6 and its supported pole pieces 14 and 15 up due to the turnin of the stud 12 closer to the diaphragm 20 which is clamped in position by the cap 31. The disk 6 in its-upward movement, which is caused by the springs 8 is guided by the pins 3 which extend up into the aligned orifices 7 in the disk 6 and the pins 3 in addition to serving as means for guiding this upward movement of the disk 6 and its sup ported parts as a whole also prevent the disk 6 from tilting in its movement and also prevent the disk 6 from turning when the ad justing stud 12 is turned. To move the disk 6 and its supported pole pieces 14 and 15 down to widen the air gap between the pole pieces 14 and 15 and the diaphragm 20, the stud 12 is turned in a counterclockwise direction and this rotation of the stud 12 draws the disk 6 and its supported pole pieces 14 and 15 down against the tension of the helical springs 8. The helical springs 8 around the pins 3 are placed under compression when the stud 12 and disk 6 are connected through the medium of their threaded the springs 8 tends to force the disk 6 and its supported parts up causing the face of the head 13 of the stud 12 to be held in frictional engagement with the face 61' of the base 4 of the cup member 2 and this friction between these two faces 60 and 61 is suificient to hold the stud 12 against movement afternation with the guide pins 3 permit vertical movement of the disk 6 as it rests upon the spring 8 at three points e uidistant apart and the threaded stud 12 w en turned in a clockwise or counterclockwise direction to permit movement of the disk 6 throu h the agency of the springs 8 causes the dis 6 to move up or down without tilting.

.Referring now to Fig. 6 I illustrate, dia-' grammatically the apparatus of the reproducer of my invention showin the permanent magnet 23 and the magnet coils repas been set. The

the pole 65 ers now in use is an object of my inresented by the windings 21 and 22. current passes through the winding 21 on the pole piece 14 in one direction and increases to maximum the magnetism of the to a maximum and the pole piece 15 has decreased.

Now as the current decreases to normal the force set up in the pole piece 14 decreases until it reaches its normal oint. whereas the pole piece 15 will buil up until it reaches its normal point. As the force of the pole piece 14 decreases the diaphragm 20 is released but the building up of the force of the polepiece 15 tends to retard the movement of diaphragm 20 and this action of the attraction of the ole piece 15 tends to act as a check or bu er and prevents the diaphragm 20 from springing back with a snap. This action of the ,forces of the pole pieces 14 and 15 with current passing through their windings 21 and 22 permits the diaphragm 20 to follow the impulses of current which pass through the windings 21 and 22 on the pole pieces 14 and 15. The windings 21 and .22 on the pole.

ieces 14 and 15 are both wound in the same direction but the inside terminal windin 80 of the winding 21 on the pole piece 14 w ich is connected to the outside terminal winding 81 of the winding 22 on the pole piece 15 produces this efiect upgn the pole pieces14 and 15 as above descri d to affect the vibration of the diaphragm 20 so as to prevent an dip ing. Y

ith t a reproducer constructed and its. windings 14 and 15 connected as. just described the objections to reproducers or loud speaker units now in use is overcome as the action of the pole pieces 14 and 15 on the diaphragm 20 prevents the area of the diaphragm at the pole piecesfirom dipping. This dipping and the ripple accompanying it is causedby the pull exerted by the pole pieces and their release, as the current decreases to normal, and is the cause of much of the distortion. To overcome this action in the re roducer by the cushioning action of the po e pieceswhich prevents this di ping as is experienced in the loud spea vention.

While I have illustrated and described a preferred embodiment of my invention it is to be understood that changes and modifica tions will readilysuggest themselves to those.

skilled in the art and I therefore aim to cover all such changes as come within the spirit and scope of the appended claims.

Having described my invention what I claim as new and desire to secure by United States Letters Patent is: v

1. A device of the character described including a permanent magnet and'a pair of pole pieces, a diaphragm normally held under stress by said magnet and pole pieces, windings for said pole pieces so connected that the excursion of movement of the diaphragm is dampened when undulating cur rent is passed through said winding.

2. A device ofthe character described including a magnet and a pair of pole pieces, a diaphragm associated with said pole pieces, windings for said pole pieces so connected that when current is passed through the same in one direction, one pole piece tends to exert a force on said diaphragm while the other pole piece tends to ampen its movement.

3. A device of the character described ineluding a magnet and a pair of ole pieces, a diaphragm associated with sai pole pieces and located on one side of said pole pieces, windings for said pole pieces so connected that when current is passed through the same in one direction-one pole piece is further magnetized while the other pole piece tends to demagnetize.

4. A device of the character described includin a magnet and a pair of pole pieces, a diap ragm associated with said pole pieces and located above said pole pieces, windings for said pole pieces so connected that when the current undulates therethrough the pole pieces alternate in becoming further magnetized and de-magnetized.

5. A device of the character described, including a diaphragm, a magnet and a pair of (pole pieces located below said diaphragm an exerting a force thereupon, windings for said pole pieces so connected that the excursion of movement ofsaid diaphragm is dampened when undulating current is passed through said windings.

6. A device of the character described, including a diaphragm, a magnet and a pair of pole pieces located below said diaphragm and exerting a ,force thereupon, windings for said pole pieces so connected that when current is passed through the same in one direction one pole piece tends to exert a force on said diaphragm while the other pole piece tends to dampen its movement.

7. A device of the character described including a diaphragm, a magnet and a pair of-(pole pieces located below said diaphragm an exerting a force thereupon, windings for said pole pieces so connected that when current is passed through the same in one direction the field density of one pole piece is increased while the field density of the other pole piece is lessened.

8. A device of the character described, including a diaphragm,

of pole pieces located below said diaphragm a magnet and a pair and exerting a force thereupon, windings for said pole pieces so connected that when undulatory current is passedthrough the same the pole pieces alternate in 5 further magnetized and demagnetized.

9. A device of the character described, including a magnet and a pair of pole pieces therefor, a diaphragm associated therewith,

becoming' windiggs for said pole ieces, said windings adapt to "be connecte to prevent dipping-10 of the diaphragm.

Signed by me at Chica o, in the county of Cook, State of Illinois, t is 23d day of December, 1924.

HARRY H. IDE. 

